1. Field of the Invention
The present invention relates to the fields of solder removal system for installing and removing microelectronic multi-sided surface mount ("surmo") devices; surmo-multi-sided wick; apparatus and techniques for producing such surmo wick from welded braid; modified multi-sided solder tip with vacuum capability and process of using such solder tip.
2. Description of the Prior Art
Solder removal systems, in general, are formed by the combination of a soldering iron for heating and a solder-pulling wick for removing such melted solder. Solder-pulling wicks, such as those disclosed in U.S. Pat. No. 3,627,191, entitled "Solder Wick" to Hood, which is incorporated herein by reference, have been used to quickly and economically remove a solder connection. Such wicks are made of metal, generally copper, strands braided to provide a capillary surface. Flux is applied to overcoat the wick so that flux need not be separately applied to the solder connection. In operation, the wick is placed on the solder connection and the connection is heated through the wick with a soldering iron, such as the commercial SC-5000 sold by Solder Removal Company or those disclosed in U.S. Pat. No. 3,990,863, entitled "Integrated-Circuit Block Extraction Tool", to Palmer, which is incorporated herein by reference. The solder melts and is drawn up into the wick by capillary forces. However, it has been found that though the conventional solder removal system works well on removing solder from conventional electronic components from a circuit board, it tends to damage the small gull-wing leads on a multi-sided semiconductor device during device installing or removal. The installing or removal process is also very cumbersome as solder has to be melted and/or removed one side at a time, leaving hot solder to flow at the edges which can damage the heat sensitive surface mount device ("SMD"). For example, the integrated-circuit block extraction tool as disclosed in U.S. Pat. No. 3,990,863 above, does not provide for means to remove the solder from each side of the device separately or simultaneously during the extraction process. Thus, the solder is likely to flow along the gull-wing leads during the solder melting step and will remain on the tip of the integrated circuit when it is extracted. This solder-flow and residue problem severely limits the block extraction tool's application in removal of multi-sided, such as rectangular or square, semiconductors mounted on the surface of a circuit board with sensitive gull-wing leads extending on four sides of the device.